Automated System for Fast and Accurate Analysis of SF6 Injected in the Surface Ocean

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• 作者：Chul-Min Koo ; Kitack Lee ; Miok Kim ; and Dae-Ok Kim
• 刊名：Environmental Science & Technology
• 出版年：2005
• 出版时间：November 1, 2005
• 年：2005
• 卷：39
• 期：21
• 页码：8427 - 8433
• 全文大小：380K
• 年卷期：v.39,no.21(November 1, 2005)
• ISSN：1520-5851

文摘

This paper describes an automated sampling and analysissystem for the shipboard measurement of dissolvedsulfur hexafluoride (SF₆) in surface marine environmentsinto which SF₆ has been deliberately released. This underwaysystem includes a gas chromatograph associated withan electron capture detector, a fast and highly efficient SF₆-extraction device, a global positioning system, and adata acquisition system based on Visual Basic 6.0/C 6.0.This work is distinct from previous studies (1, 2) in that itquantifies the efficiency of the SF₆-extraction device andits carryover effect and examines the effect of surfactant onthe SF₆-extraction efficiency. Measurements can becontinuously performed on seawater samples taken froma seawater line installed onboard a research vessel. Thesystem runs on an hourly cycle during which one set of fourSF₆ standards is measured and SF₆ derived from theseawater stream is subsequently analyzed for the rest ofeach 1 h period. This state-of-art system was successfullyused to trace a water mass carrying Cochlodiniumpolykrikoides, which causes harmful algal blooms (HAB)in the coastal waters of southern Korea. The successfulapplication of this analysis system in tracing the HAB-infectedwater mass suggests that the SF₆ detection methoddescribed in this paper will improve the quality of thefuture study of biogeochemical processes in the marineenvironment.